Place oil, water and garlic in a very large pot; heat over medium high heat, then add the chopped Savoy cabbage, stir and cover with the lid. Let cook for another 5 minutes, then stir once more. Now add the dandelion greens and kale (and/or chard) and continue to cook over medium heat, covered, stirring now and then, for about 10 minutes. Add salt, pepper and the fennel seeds. Check to make sure the liquid has not dried up, if so, add more water. Add the spinach, and cook for another 5 minutes or so.
Next, add the beans and mix well into the minestra. Taste for salt and pepper, and continue to cook for just a few minutes until the beans are heated through. Serve with fresh crusty bread and slices of fresh, sweet onion.